Electric angle steel tower Electric angle steel tower is a kind of steel structure which can keep a certain safe distance between the supporting conductors and the ground buildings in the transmission line. In the 1980s, many countries in the world began to apply steel pipe profiles to the tower structure when developing UHV transmission lines. Steel tube towers with steel pipes as the main material appeared. In Japan, steel tube towers are almost used in 1000kV UHV lines and towers. They have a thorough research on the design technology of steel pipe poles. Drawing on foreign experience, steel pipe profiles have been used in 500kV Double Circuit Tower and four circuit tower on the same tower in China, which shows its good performance and benefit. Due to its large section stiffness, good cross-section stress characteristics, simple stress, beautiful appearance and other outstanding advantages, steel tube tower structure has been well developed in different voltage level lines. Especially, it is widely used in large span structure and tower structure of urban power grid. With the continuous development of China's metallurgical industry, the production of high-strength steel is no longer difficult. The quality of high-strength structural steel in China has been improved rapidly and steadily, and the supply channel has become increasingly smooth, which provides the possibility of using high-strength steel in transmission line towers. In the preliminary research project of 750 kV transmission line, the Electric Power Construction Research Institute of state power corporation has studied the joint connection structure, component design parameter value, matching bolts and economic benefits that will be encountered in the use of high-strength steel. It is considered that the high-strength steel has fully met the conditions for use in the tower from the technology and application, and the use of high-strength steel can be reduced The weight of the tower is 10% - 20%.